Currently, Searchie supports uploads of up to 6GB at a time (per file) so very lengthy video/audio with high picture/sound quality might exceed the limit. There is also a time limit on the upload of 4 hours (per file). Ways to work around this may be to compress your video or export it in a lower quality resolution. Searchie may expand its upload limit size in the future for users.
If you are having general trouble getting a video to upload, check out this help article.